Breast cancer survivors represent a significant and growing segment of the long-term cancer survivor population. While more patients are living disease-free, they frequently are not symptom-free as problems may persist that affect both emotional (depression and anxiety) and physical (weight gain, fatigue, lymphedema) functioning. Although research indicates quality of life may be compromised in breast cancer survivors, no studies have attempted to provide a comprehensive intervention that targets multiple quality of life domains in these women. Previous studies suggest that psychological interventions may result in improvements in emotional well-being, but they are not effective in alleviating physical symptoms or restoring physical functioning. Physical activity has been demonstrated to have a positive effect on both emotional well-being and physical functioning. A physical activity intervention may serve as a tertiary prevention strategy that increases the quality of life of breast cancer survivors because of its potential effectiveness in targeting both emotional and physical symptoms that persist. Data from the Lifestyle Physical Activity (LPA) intervention from Project Active, on which our LPA intervention will be based, suggests that accumulating short bouts of moderate physical activity throughout the day results in increases in physical activity and fitness, and decreases in cardiovascular risk factors. Other studies indicate physical activity improves overall quality of life, including both emotional and physical well-being. The proposed project will involve collecting data to adapt the LPA intervention for breast cancer survivors and pilot test the intervention. Using interviews and questionnaires, we will conduct a descriptive study of breast cancer survivors to assess their quality of life, the prevalence of specific health and emotional problems, levels of physical activity, and preferences regarding intervention format and logistics. We will also pilot test proposed questionnaires to assess their psychometric properties in the population. Finally, we will pilot test the LPA intervention, conduct process evaluation, and explore its effects on mediating (physical activity, self-efficacy, decisional balance, processes of change, social support) and the outcome variables (emotional well-being and physical functioning). The information obtained in this pilot project will be used to propose a larger group randomized trial of the LPA intervention in the breast cancer survivor population.